A dual-frequency low-orbit occultation GNSS antenna

Abstract

The present invention discloses a dual-frequency low-orbit occultation GNSS antenna, comprising an antenna unit, wherein the antenna unit comprises a first dielectric plate, a second dielectric plate, a third dielectric plate, a fourth dielectric plate and a metal bottom plate, wherein the first dielectric plate is printed with a first microstrip patch, the first dielectric plate is provided with a metallized via, the second dielectric plate is printed with a second microstrip patch, the second microstrip patch is provided with a gap, the third dielectric plate is provided with a feeding network, the fourth dielectric plate and the third dielectric plate are bonded together to form a stripline feeding network, and the first dielectric plate, the second dielectric plate, the metal bottom plate, the third dielectric plate and the fourth dielectric plate are stacked from top to bottom. The present invention realizes a 2×2 equal-amplitude and in-phase, GPS / BDS compatible, miniaturized, lightweight uniform array low-orbit occultation GNSS antenna.

Description

Technical Field

[0001] The present invention relates to the field of space exploration instruments, and in particular to a dual-frequency low-orbit occultation GNSS (Global Navigation Satellite System) antenna. Background Art

[0002] When GNSS signals pass through the ionosphere and atmosphere and reach the low-orbit satellite at the other end, additional delay and bending will occur due to the existence of the propagation medium and its gradient. Using this additional delay and bending information, based on certain assumptions, the ionosphere electron density and the refractive index, temperature, density, and water vapor content of the lower atmosphere can be inverted. As an indispensable part of the satellite-borne occultation detection system, the performance of the antenna directly affects the performance of the entire system. Since satellite platforms, especially microsatellites, hope that the on-board equipment is as small and lightweight as possible, conventional GNSS antennas cannot meet the needs of occultation detection systems. Summary of the invention

[0003] In view of this, the present invention provides a dual-frequency low-orbit occultation GNSS antenna, which realizes a 2×2 equal-amplitude and same-phase, GPS / BDS-compatible, miniaturized, and lightweight low-orbit occultation GNSS antenna.

[0004] The present invention provides a dual-frequency low-orbit occultation GNSS antenna, comprising an antenna unit, wherein the antenna unit comprises a first dielectric plate, a second dielectric plate, a metal base plate, a third dielectric plate and a fourth dielectric plate, wherein the first dielectric plate is printed with a first microstrip patch, the first dielectric plate is provided with a metallized via, the second dielectric plate is printed with a second microstrip patch, the second microstrip patch is provided with a gap, the third dielectric plate is provided with a feeding network, the fourth dielectric plate and the third dielectric plate are bonded together to form a stripline feeding network, and the first dielectric plate, the second dielectric plate, the metal base plate, the third dielectric plate and the fourth dielectric plate are stacked from top to bottom.

[0005] Furthermore, the first dielectric plate and the first microstrip patch are concentrically arranged, the metallized via is located at the center of the first dielectric plate, and the first microstrip patch is a high-frequency microstrip patch, and its operating frequency includes 1575.42 MHz and 1561.098 MHz.

[0006] Furthermore, the second dielectric plate and the second microstrip patch are concentrically arranged, the gap includes four centrosymmetrical L-shaped gaps, the center position of the gap is the same as the center position of the second microstrip patch, and the second microstrip patch is a low-frequency microstrip patch, and its operating frequency includes 1227.6MHz and 1207.14MHz.

[0007] Furthermore, the first dielectric plate and the first microstrip patch are provided with first probe holes corresponding to the same position, the second dielectric plate is provided with a coupling hole, the coupling hole is located in two axially symmetrical L-shaped gaps of the gap, and the metal base plate is also provided with a third probe hole corresponding to the position, and the first probe hole, the coupling hole and the third probe hole are all used to install the same probe.

[0008] Furthermore, the first microstrip patch is welded to the third dielectric plate through the probe, and the first microstrip patch is directly fed by the probe; the second microstrip patch is connected to the third dielectric plate in a coupled form, and the second microstrip patch is coupled fed.

[0009] Furthermore, a small triangle is cut off from two opposite right angles of the first microstrip patch, and a small triangle is cut off from two corresponding right angles of the second microstrip patch.

[0010] Furthermore, the dielectric constant of the first dielectric plate is 10, the dielectric constant of the second dielectric plate is 6.15, the dielectric constants of the third dielectric plate and the fourth dielectric plate are both 3.5, and the metal bottom plate is made of aluminum alloy.

[0011] Furthermore, an SMA-K connector is provided on the lower surface of the third dielectric plate, serving as an output port of the entire antenna.

[0012] Furthermore, there are four antenna units arranged in a 2×2 array.

[0013] Furthermore, the first dielectric plate and the second dielectric plate are fixed above the metal bottom plate by screws, and the third dielectric plate and the fourth dielectric plate are fixed below the metal bottom plate by screws.

[0014] Compared with the existing technology, the present invention has the following beneficial technical effects:

[0015] The present invention provides a dual-frequency low-orbit occultation GNSS antenna. By opening a metallized via on a first-layer dielectric board and opening four centrosymmetrical L-shaped slots on a second microstrip patch, the size of the patch is reduced, thereby reducing the size of the antenna, making the antenna miniaturized and lightweight. At the same time, a dual-frequency stacked microstrip patch is adopted, which can respectively cover the L1 and L2 frequency bands of GPS and the B1 and B2 frequency bands of a BDS system, thereby realizing a 2×2 equal-amplitude and in-phase, GPS / BDS-compatible, miniaturized and lightweight low-orbit occultation GNSS antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1This is a structural exploded diagram of a dual-frequency low-orbit occultation GNSS antenna of the present invention;

[0017] Figure 2 The figure is a top view of a dual-frequency low-orbit occultation GNSS antenna according to the present invention.

[0018] Among them: 10-first layer of dielectric plate; 11-first microstrip patch; 12-metallized via; 13-first probe hole; 20-second layer of dielectric plate; 21-second microstrip patch; 22-gap; 23-coupling hole; 30-third layer of dielectric plate; 40-fourth layer of dielectric plate; 50-metal bottom plate; 53-third probe hole. DETAILED DESCRIPTION

[0019] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] In the description of the present invention, it should be noted that the orientation or position relationship indicated in the description is based on the orientation or position relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] Please refer to Figure 1-2 The present invention provides a dual-frequency low-orbit occultation GNSS antenna, comprising an antenna unit, the antenna unit comprising a first dielectric plate 10, a second dielectric plate 20, a metal base plate 50, a third dielectric plate 30 and a fourth dielectric plate 40, the first dielectric plate 10 is printed with a first microstrip patch 11, the first dielectric plate 10 is provided with a metallized via 12, the second dielectric plate 20 is printed with a second microstrip patch 21, the second microstrip patch 21 is provided with a gap 22, the third dielectric plate 30 is provided with a feeding network, the fourth dielectric plate 40 and the third dielectric plate 30 are bonded together to form a stripline feeding network, the first dielectric plate 10, the second dielectric plate 20, the metal base plate 50, the third dielectric plate 30 and the fourth dielectric plate 40 are stacked from top to bottom.

[0022] Specifically, the first dielectric plate 10 and the first microstrip patch 11 are concentrically arranged. The shape of the first dielectric plate 10 is approximately rectangular, and each side is provided with a lug. The shape of the first microstrip patch 11 is also approximately rectangular, and each side is provided with a tuning branch. A small triangle is cut off at two opposite right angles of the first microstrip patch 11 to realize the circular polarization operation of the antenna. The metallized via 12 is located at the center of the first dielectric plate 10. The first microstrip patch 11 is a high-frequency microstrip patch, and its operating frequencies include 1575.42MHz and 1561.098MHz, which is used to receive GNSS signals in the L1 / B1 frequency band. The second dielectric plate 20 and the second microstrip patch 21 are concentrically arranged. The second dielectric plate 20 is rectangular in shape, and the second microstrip patch 21 is approximately rectangular in shape, and each side is provided with a tuning branch. Correspondingly, two of the opposite right angles of the second microstrip patch 21 also cut off a small triangle to achieve circular polarization of the antenna. The slot 22 is 4 centrosymmetrical L-shaped slots, and the center position of the slot 22 is the same as the center position of the second microstrip patch 21. The second microstrip patch 21 is a low-frequency microstrip patch, and its operating frequency includes 1227.6MHz and 1207.14MHz, which is used to receive GNSS signals in the L2 / B2 frequency band. It should be noted that the dielectric constants of the first dielectric plate 10 and the second dielectric plate 20 are not limited. In this embodiment, the dielectric constant of the first dielectric plate 10 is 10, and the dielectric constant of the second dielectric plate 20 is 6.15. The low-orbit occultation GNSS antenna provided by the present invention can respectively cover the L1 and L2 frequency bands of the GPS (Global Positioning System) and the B1 and B2 frequency bands of the BDS system (Beidou Satellite Navigation System) by adopting a dual-frequency stacked microstrip antenna form, that is, the two frequencies of 1575.42MHz and 1227.6MHz are suitable for the working frequency band of the GPS system, and the two frequencies of 1561.098MHz and 1207.14MHz are suitable for the working frequency band of the BDS system, thereby achieving GPS / BDS compatibility.

[0023] Since the feeding points of the first microstrip patch 11 and the second microstrip patch 21 need to be at the same position and need to be matched to the antenna impedance of 50 ohms at the same time, it is difficult to achieve. Therefore, in the present invention, by opening four centrosymmetrical L-shaped gaps on the second microstrip patch 21, the propagation path of the current on the patch is changed, the equivalent path of the current is lengthened, the size of the patch is reduced, and the miniaturization and lightweight of the antenna are achieved. In addition, since the first microstrip patch 11 and the second microstrip patch 21 are fed using the same probe, it is necessary to reasonably select the feeding point so that the first microstrip patch 11 and the second microstrip patch 21 are matched at the same time. In the present invention, by opening a metallized via 12 at the center position of the first dielectric plate 10, the capacitance of the first microstrip patch 11 is increased, and its matching point is moved to the edge of the patch, which is conducive to adjusting the first microstrip patch 11 and the second microstrip patch 21 to match at the same feeding point while miniaturizing the second microstrip patch 21.

[0024] Furthermore, the first dielectric plate 10 and the first microstrip patch 11 are provided with corresponding first probe holes 13, the second dielectric plate 20 is provided with coupling holes 23, the coupling holes 23 are located in two axisymmetric L-shaped slots of the slot 22, and the metal bottom plate 50 is provided with corresponding third probe holes 53, the first probe hole 13, the coupling hole 23 and the third probe hole 53 are all used to install the same probe. The position of the probe is determined according to the coupling impedance of the first microstrip patch 11 and the second microstrip patch 21. The coupling impedance is affected by the thickness of the first dielectric plate 10 and the second dielectric plate 20, the dielectric constant, the size of the first microstrip patch 11 and the second microstrip patch 21 and other parameters.

[0025] Furthermore, a feeding network is printed on the lower surface of the third dielectric plate 30, and the fourth dielectric plate 40 and the third dielectric plate 30 are bonded together to form a stripline feeding network. The output end of the feeding network is connected to the SMA-K connector, and the SMA-K connector is arranged on the lower surface of the third dielectric plate 30 as the output port of the entire antenna. The first microstrip patch 11 is welded to the third dielectric plate 30 through a probe, and the first microstrip patch 11 is directly fed by the probe; the second microstrip patch 21 is connected to the third dielectric plate 30 in a coupled form, and the second microstrip patch 21 is coupled and fed. It should be noted that the dielectric constants of the third dielectric plate 30 and the fourth dielectric plate 40 are not limited. In this embodiment, the dielectric constants of the third dielectric plate 30 and the fourth dielectric plate 40 are both 3.5.

[0026] Specifically, the first dielectric plate 10 and the second dielectric plate 20 are fixed above the metal bottom plate 50 by screws, and the third dielectric plate 30 and the fourth dielectric plate 40 are fixed below the metal bottom plate 50 by screws.

[0027] It should be noted that the number of antenna units is not limited and can be adjusted according to actual needs, but multiple antenna units are arranged in an array. In this embodiment, there are 4 antenna units arranged in a 2×2 array.

[0028] From the above description, it can be known that the dual-frequency low-orbit occultation GNSS antenna provided by the present invention reduces the size of the patch by opening a metallized via on the first dielectric board and opening four centrally symmetrical L-shaped slots on the second microstrip patch, thereby reducing the size of the antenna, making the antenna miniaturized and lightweight. At the same time, a dual-frequency stacked microstrip patch is used to cover the L1 and L2 frequency bands of GPS and the B1 and B2 frequency bands of the BDS system, respectively, realizing a 2×2 equal-amplitude and in-phase, GPS / BDS compatible, miniaturized, lightweight uniform array low-orbit occultation GNSS antenna.

[0029] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A dual-frequency low-orbit occultation GNSS antenna, characterized in that: The invention comprises an antenna unit, wherein the antenna unit comprises a first dielectric plate (10), a second dielectric plate (20), a third dielectric plate (30), a fourth dielectric plate (40) and a metal base plate (50); a first microstrip patch (11) is printed on the first dielectric plate (10); a metalized via hole (12) is provided on the first dielectric plate (10); a second microstrip patch (21) is printed on the second dielectric plate (20); a slot (22) is provided on the second microstrip patch (21); a feeding network is provided on the third dielectric plate (30); and a metal base plate (50) is provided on the fourth dielectric plate (40). 0) and the third dielectric plate (30) are bonded together to form a stripline feeding network; the first dielectric plate (10), the second dielectric plate (20), the metal base plate (50), the third dielectric plate (30) and the fourth dielectric plate (40) are stacked from top to bottom; the first microstrip patch (11) is a high-frequency microstrip patch, and its operating frequency includes 1575.42 MHz and 1561.098 MHz; the second microstrip patch (21) is a low-frequency microstrip patch, and its operating frequency includes 1227.6 MHz and 1207.14 MHz.

2. The dual-frequency low-orbit occultation GNSS antenna according to claim 1, characterized in that: The first dielectric plate (10) and the first microstrip patch (11) are arranged concentrically, and the metallized via (12) is located at the center of the first dielectric plate (10).

3. The dual-frequency low-orbit occultation GNSS antenna according to claim 2, characterized in that: The second dielectric plate (20) and the second microstrip patch (21) are arranged concentrically, the slot (22) comprises four centrosymmetric L-shaped slots, and the center position of the slot (22) is the same as the center position of the second microstrip patch (21).

4. The dual-frequency low-orbit occultation GNSS antenna according to claim 1, characterized in that: The first dielectric plate (10) and the first microstrip patch (11) are provided with corresponding first probe holes (13); the second dielectric plate (20) is provided with a coupling hole (23); the coupling hole (23) is located in two axially symmetrical L-shaped slots of the slot (22); the metal bottom plate (50) is provided with a third probe hole (53) at a corresponding position; the first probe hole (13), the coupling hole (23) and the third probe hole (53) are all used to install the same probe.

5. The dual-frequency low-orbit occultation GNSS antenna according to claim 4, characterized in that: The first microstrip patch (11) is welded to the third dielectric plate (30) via the probe, and the first microstrip patch (11) is directly fed by the probe; the second microstrip patch (21) is connected to the third dielectric plate (30) in a coupled form, and the second microstrip patch (21) is coupled fed.

6. The dual-frequency low-orbit occultation GNSS antenna according to claim 3, characterized in that: A small triangle is cut off from two opposite right angles of the first microstrip patch (11), and a small triangle is cut off from two corresponding right angles of the second microstrip patch (21).

7. The dual-frequency low-orbit occultation GNSS antenna according to claim 3, characterized in that: The dielectric constant of the first dielectric plate (10) is 10, the dielectric constant of the second dielectric plate (20) is 6.15, the dielectric constants of the third dielectric plate (30) and the fourth dielectric plate (40) are both 3.5, and the metal bottom plate (50) is made of aluminum alloy.

8. The dual-frequency low-orbit occultation GNSS antenna according to claim 1, characterized in that: The lower surface of the third dielectric plate (30) is provided with an SMA-K connector, which serves as an output port of the entire antenna.

9. The dual-frequency low-orbit occultation GNSS antenna according to claim 1, characterized in that: There are four antenna units arranged in a 2×2 array.

10. The dual-frequency low-orbit occultation GNSS antenna according to claim 1, characterized in that: The first dielectric plate (10) and the second dielectric plate (20) are fixed above the metal bottom plate (50) by means of screws, and the third dielectric plate (30) and the fourth dielectric plate (40) are fixed below the metal bottom plate (50) by means of screws.

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